Conventional movable partition wall systems usually take the form of horizontally sliding panels, and are used for example to close or section off areas in buildings. These types of partition wall systems usually require storage space beside the area being closed off, to accommodate the panels when not in use.
U.S. Pat. No. 5,062,464 of Miles Peterson, issued Nov. 5, 1991 describes and illustrates a partition wall which uses a pantograph type of construction to provide a rigid wall section, which is vertically collapsible and movable to a storage position. Conventional horizontally movable partition wall systems have problems of efficient storage and require additional structural support requirements. The Peterson vertically movable partition wall avoids those problems by providing ceiling storage for the partition wall and a single permanent location for all of the panels so that the loads imposed on the building support structure do not vary since there is no horizontal movement of the panels. Further, this design of the wall system allows the partition to be of any width or height as it is lifted and supported at multiple points across its width.
The pantograph structure as suggested by this Peterson construction is similar to that for instance found in baby gates in which a series of elongated members are pivotally linked together in spaced fashion to provide a series of similar diamonds along the length of the gate. In a single (as opposed to multiple) pantograph construction, a pair of members of similar size are pivotally linked at their midpoints. One pair of their ends are pivotally linked to the ends of a further corresponding pair of members of similar length similarly pivoted at their midpoint, and so on. The midpoints of the members are longitudinally aligned and form opposed longitudinal apexes of diamond shapes; the other opposed corners of these diamonds are formed by the pivotally secured ends of adjacent pairs of intersecting members, and are the lateral apexes. The pantograph structure expands and contracts longitudinally. The pantograph structure in such applications is useful because it causes forces applied longitudinally, in the direction of expansion and contraction of the pantograph, to be transmitted evenly throughout all of the members of the pantograph structure. As well, all of the apexes of the diamonds formed by the points of intersection of the members, as the structure is contracted, will arrive at their final, fully contracted position at the same time, meaning that the longitudinal apexes of the diamonds at one end of the pantograph structure, which are moving towards the other end during contraction, will move at a much greater speed than the apexes of the diamonds at the other end.
It is an object of the present invention to provide a movable partition wall which is based on these pantograph principles.